Repair of sub-lethal freezing damage in leaves of Arabidopsis thaliana

The detrimental effects of global climate change direct more attention to the survival and productivity of plants during periods of highly fluctuating temperatures. In particular in temperate climates in spring, temperatures can vary between above-zero and freezing temperatures, even during a single day. Freeze-thaw cycles cause cell membrane lesions that can lead to tissue damage and plant death. Whereas the processes of cold acclimation and freeze-thaw injury are well documented, not much is known about the recovery of plants after a freezing event. We therefore addressed the following questions: i. how does the severity of freezing damage influence repair; ii. how are respiration and content of selected metabolites influenced during the repair process; and iii. how do transcript levels of selected genes respond during repair

Randomized controlled trials – a matter of design

Peter Markus Spieth,1,2 Anne Sophie Kubasch,3 Ana Isabel Penzlin,4 Ben Min-Woo Illigens,2,5 Kristian Barlinn,6 Timo Siepmann2,6,7 1Department of Anesthesiology and Critical Care Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, 2Center for Clinical Research and Management Education, Division of Health Care Sciences, Dresden International University, 3Pediatric Rheumatology and Immunology, Children’s Hospital, University Hospital Carl Gustav Carus, Technische Universität Dresden, 4Institute of Clinical Pharmacology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Saxony, Germany; 5Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; 6Department of Neurology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Saxony, Germany; 7Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, Oxfordshire, UK Abstract: Randomized controlled trials (RCTs) are the hallmark of evidence-based medicine and form the basis for translating research data into clinical practice. This review summarizes commonly applied designs and quality indicators of RCTs to provide guidance in interpreting and critically evaluating clinical research data. It further reflects on the principle of equipoise and its practical applicability to clinical science with an emphasis on critical care and neurological research. We performed a review of educational material, review articles, methodological studies, and published clinical trials using the databases MEDLINE, PubMed, and ClinicalTrials.gov. The most relevant recommendations regarding design, conduction, and reporting of RCTs may include the following: 1) clinically relevant end points should be defined a priori, and an unbiased analysis and report of the study results should be warranted, 2) both significant and nonsignificant results should be objectively reported and published, 3) structured study design and performance as indicated in the Consolidated Standards of Reporting Trials statement should be employed as well as registration in a public trial database, 4) potential conflicts of interest and funding sources should be disclaimed in study report or publication, and 5) in the comparison of experimental treatment with standard care, preplanned interim analyses during an ongoing RCT can aid in maintaining clinical equipoise by assessing benefit, harm, or futility, thus allowing decision on continuation or termination of the trial. Keywords: randomized clinical trials, RCT, validity, study design, CONSOR

Cardiac dysautonomia in depression – heart rate variability biofeedback as a potential add-on therapy

Alexandra Pinter,1,2 Szabolcs Szatmari Jr,1,3–4 Tamas Horvath,5 Ana Isabel Penzlin,6 Kristian Barlinn,7 Martin Siepmann,8 Timo Siepmann1,71Division of Health Care Sciences, Dresden International University, Dresden, Germany; 2Department of Family Medicine, Semmelweis University, Budapest, Hungary; 3Department of Neurology, Semmelweis University, Budapest, Hungary; 4Janos Szentagothai Doctoral School of Neurosciences, Semmelweis University, Budapest, Hungary; 5Department of Hydrodynamic Systems, Budapest University of Technology and Economics, Budapest, Hungary; 6Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; 7Department of Neurology, Carl Gustav Carus University Hospital, Technische Universität Dresden, Dresden, Germany; 8Department of Psychosomatic Medicine and Psychotherapy, Carl Gustav Carus University Hospital, Technische Universität Dresden, Dresden, GermanyAbstract: Depressive disorders are among the most important health problems and are predicted to constitute the leading cause of disease burden by the year 2030. Aside significant impact on quality of life, psychosocial well-being and socioeconomic status of affected patients, depression is associated with impaired cardiovascular health and increased mortality. The link between affective and cardiovascular disease has largely been attributed to dysregulation of the autonomic nervous system resulting in a chronic shift toward increased sympathetic and decreased parasympathetic activity and, consecutively, cardiac dysautonomia. Among proposed surrogate parameters to capture and quantitatively analyze this shift, heart rate variability (HRV) and baroreflex sensitivity have emerged as reliable tools. Attenuation of these parameters is frequently seen in patients suffering from depression and is closely linked to cardiovascular morbidity and mortality. Therefore, diagnostic and therapeutic strategies were designed to assess and counteract cardiac dysautonomia. While psychopharmacological treatment can effectively improve affective symptoms of depression, its effect on cardiac dysautonomia is limited. HRV biofeedback is a non-invasive technique which is based on a metronomic breathing technique to increase parasympathetic tone. While some small studies observed beneficial effects of HRV biofeedback on dysautonomia in patients with depressive disorders, larger confirmatory trials are lacking. We reviewed the current literature on cardiac dysautonomia in patients suffering from depression with a focus on the underlying pathophysiology as well as diagnostic workup and treatment.Keywords: mood disorder, autonomic dysfunction, cardiovascular disease, brain-heart axis, biofeedbac

The Resolution of Lens and Compound Eyes

Two distinctly different types of eyes have been highly developed in evolution: lens eyes (= camera eyes) in vertebrates, some molluscs and arachnids and compound eyes in arthropods. Based on his comparative studies of the optical properties of compound and lens eyes, Exner (1891) concluded that both types of eyes are optimally adapted for different functions: lens eyes with their high angular resolution seem to more useful for pattern recognition, whereas the compound eyes, with their poor resolution, are thought to be specialized for movement perception. This view is still generally accepted (see the textbooks of Scheer, 1969, Kaestner, 1972). Furthermore, the small facet diameters of the ommatidia in compound eyes seem to cause a poor absolute sensitivity (Exner, 1891; Barlow, 1952; Kirschfeld, 1966; Prosser and Brown, 1969; Snyder et al., 1973). Some insects are said, however, to have higher temporal resolution than humans (Autrum, 1948)